Precision, Speed, and Cost—Oh My!

Orthopedic device prototyping labs work to collude precision with short lead times and monetary concerns.

A mechanical engineer testing and measuring prototype parts in the IncisionLab. (Courtesy of Cadence Inc.)

Sam Brusco, Associate Editor11.22.16

Contrary to popular belief, the first “iPhone” prototype was actually manufactured in 1983. To be fair, it wasn’t truly a prototype—the device was far from a modern mobile phone—but it was a phone with Apple’s logo on it, which is close enough. Rather than the iPhones of today resting comfortably in millions of pockets, it resembled the corded phones quite popular at the time (and virtually nonexistent today) with one glaring exception: it apparently had a working touchscreen, complete with a stylus to interact with it.

This particular phone prototype never made it into production. Harmtut Esslinger, a man whose claim to fame involved helping to develop the Apple II desktop PC (Apple’s first “portable” computer) purportedly designed it. Thanks to Stanford University’s enormous repository of seminal Apple documents, images of many prototypes like the 1983 iPhone have made the rounds on the web—there’s even a 1983 device that looks remarkably like an iPad, complete with an attachable keyboard.

“Apple’s strategy is really simple. What we want to do is we want to put an incredibly great computer in a book that you can carry around with you and learn how to use in 20 minutes. That’s what we want to do and we want to do it this decade,” Steve Jobs said in a recording of a 1983 International Design Conference in Aspen event, which was unearthed about four years ago. “And we really want to do it with a radio link in it so you don’t have to hook up to anything and you’re in communication with all of these larger databases and other computers.”

Sounds familiar, doesn’t it? And that was more than 30 years ago.

Speaking of technological juggernauts’ early prototypes, did you know that one of Microsoft’s first iterations of the Xbox game console was actually X-shaped? Microsoft certainly opted for flair over practicality in that regard; as any Xbox owner can attest to, the design was eventually slimmed down into something that might fit better inside consumer homes. Plus, the sharp edges on that prototype would surely have been a concern for the game console’s youthful target market.

Why bring up these seemingly innocuous examples of discontinued prototypes? They aptly illustrate the direction a device can travel following its first iteration, and that designs from earlier models (even decades earlier) can make an impact on the final commercial product. Apple obviously didn’t continue developing corded phones based on that first model, but the company’s developments to touchscreen technology persisted. Landline phones are disappearing into obsolescence, but modern mobile phones may not have ended up looking or operating the way they do without Apple’s commitment to touchscreen technology development. And Microsoft learned that aesthetics aren’t everything when considering a commercial product—though echoes of the Xbox's original design can still be seen in their future game consoles.

Because of the highly regulated and cost-concerned nature of the medical technology industry, device developers can’t play quite as fast and loose with prototypes of their commercial products. Manufacturers can take a couple of approaches to the first physical iteration of their device, from a model that approximates the dimensions of the commercial product, to an actual functional technology that mimics the final product as closely as possible.

Developers of musculoskeletal devices and implants are held to an even higher standard when developing prototypes. Orthopedic devices in particular demand more precision during the prototyping process because their typical location in or on the body near bone or muscle subjects them to considerable long-term wear. However, rapidity is all the rage in the medical device world due to its lengthy product development cycles and arduous regulatory approval process. As a result, those providing prototyping services for orthopedic devices have somewhat of a juggling act to perform in colluding precision, speed, and cost.

“As a manufacturer, prototyping is always challenging with short lead times and the availability of resources. Every customer has different requests,” explained Ken Gredick, engineering manager for Upper Saddle River, N.J.-based Triangle Manufacturing. “Customers who choose to partner with us work with us under time and material purchase orders. The engineering and inspection departments from both companies work together to find an optimal solution for potential issues. This is a win-win for both companies, as the design gets optimized for manufacturing and leads to shorter production lead times as well as the potential for‘up-front’ production cost reductions. Other customers request ‘production equivalent’ parts, which require a lot more documentation, planning, and cost. In this situation, customers do not realize the production benefit of Design for Manufacturing and Design for Inspection (DFM/DFI).”

“Customers want to touch and feel a prototyped instrument or implant to quickly determine form, fit, and functionality, including aesthetics and general utility for the procedure. It’s a critical step in the product development process and is common across virtually every orthopedic or spine company in the industry,” noted James Schultz, executive vice president of sales and marketing for Thousand Oaks, Calif.-based ECA Medical Instruments. “We employ a process called rapid instrument customization to help them gain the benefits of disposable instruments for both legacy and new implants. Our focus adds speed and productivity gains in the product development process. This translates to cost savings and time to market accelerators. The future of medtech—whether orthopedic, spine, biotech, or pharma—is personalized medicine. Rapid prototyping and rapid product development are critical to developing and fielding implants and instrumentation that can have significant clinical value for common high-volume procedures, or even one patient at a time. This flexibility and the outcomes that occur will themselves become differentiators that allow existing OEMs to innovate and penetrate new markets with new customers, and take market share in existing segments.”

Naturally, it’s nearly impossible to avoid discussing additive manufacturing strategies in any discourse on prototyping, especially with lead times as a major concern. This type of prototyping strategy also lends itself well to the highly personalized nature of orthopedic devices.

“We are noticing trends for requests for 3D printed components since the FDA has produced guidelines to allow this type of manufacturing,” indicated Justin Bishop, prototype manager for Shelton, Conn.-based Orchid Design. But despite its ubiquity in the orthopedic design and development space, that’s of course not the only trend worth noting.

“We are also finding trends in minimally invasive surgical instruments and navigated instruments, allowing for higher success rates and faster patient recoveries,” Bishop noted. “There seem to be a lot of developments in spinal surgeries as well—specifically, a frequency in expandable spinal implants and fusion systems that will allow more mobility for the patient. These types of trends are driving towards smaller and more challenging components with much tighter tolerances.”

A Juggling Act
Organizations providing orthopedic device prototyping services have their hands quite full, and then some. Because these devices will be in close proximity to bone and muscle and will be jostled considerably as a result, design and dimension precision is key when creating a prototype. And while haste can be the enemy of accuracy, device developers may not even consider a prototyping partner that isn’t up to speed, so to speak. In some cases, this might mean a lab prototyping parts that are very nearly production-ready.

“Customers’ number one concern is speed, plain and simple. A customer can never get a part too soon,” said Steve Hartzog, rapid prototyping and manufacturing engineering technician for Staunton, Va.-based Cadence Inc. “New or ongoing designs require partnerships that are nimble and flexible—in fact, many prototypes may not always be created by the production process. Orthopedic customers, as with any, typically want a prototyping partner that can also scale into production. Nobody likes going to a different partner that has to ‘learn’ how to make a part that a different prototyping house initially created. A good prototyping/production partner will typically have the ‘end game’ in mind, with thoughts on how to move to production after manufacturing the initial prototypes.”

“Some key features customers look for in prototyping partners are responsiveness, speed, skill, innovation, and communication. Responsiveness and speed go hand-in-hand and are necessary, especially with how fast technologies are changing,” illustrated Bishop. “The ultimate goal with speed of prototyping is time-to-market. The faster you can test prototypes and iterate designs ultimately leads to the product getting on the market quickly. Skill is critical because of the complexity and difficulty of the prototype manufacturing process. Devices are ultimately designed to give the best possible outcome for the patient; therefore, the limits of manufacturability are pushed. Communication is another key factor, as we have learned customers appreciate feedback and an open dialog while prototyping. We oftentimes become the second set of eyes for blueprints and CAD models and help with DFM catching things that would ultimately help with ease of manufacturing both from a cost and manufacturability standpoint.”

Of course, it would be irresponsible to only seek out the fastest prototyping services. While medical device development may often seem like a race to market, it’s also important that manufacturers pay attention to factors like the ability to perform DFM services, and the quality systems the firm providing orthopedic device prototyping has in place.

“Customers look for design for manufacturing assistance,” explained Ed Duhaime, senior project engineer at Cadence Inc.’s Cranston, R.I. facility. “They want a supplier that can make prototypes and quickly transition into production and scale up to meet market demands. They also want a supplier with a robust quality system in place.”

“Some key features customers seeking prototyping services look for: fast turnaround, good collaboration between OEM and manufacturing engineering, good quality work, a good quality management system, and a facility that can handle both prototyping and production,” noted Gredick.

Having engineers close to the shop is also good practice for a prototyping lab. (Truthfully, having engineers involved in essentially all areas of the production cycle is likely good practice.)

“We have learned that having our design engineers working side-by-side with our prototype technicians is a significant competitive advantage,” said Bishop. Our engineers are within feet of the prototype shop, and the ability for the engineers to get real-time feedback from our technicians is very valuable. Additionally, the engineers are available instantly to answer questions and make sure their prototypes are progressing per plan.”

Quick and Nimble
Since customers seem to be looking for speed above all from their prototyping partners, additive manufacturing technology’s advent comes at quite the opportune time. It seems to be the go-to prototyping method for that reason, but it also offers further benefits to orthopedic device manufacturers. For example, 3D printing can provide a solution for prototyped parts that can’t be produced with conventional machining strategies. Questions do still arise about its costliness and practicality, but prototyping service providers are perhaps the group that most benefits from the technology.

“We create 3D printed parts on virtually 100 percent of our new product development programs. It’s a fantastic productivity tool in the design and development process,” explained Schultz. “The ability to mix materials and create instruments in near real-time that can be tested in proof-of-concept or voice of the customer (VoC) conditions adds huge value to any design and development department. Coupled with state-of-the-art CAD/CAM products, finite element analysis linear and non-linear software suites, mold flow tools, and other contemporary design and development products, the engineering department has a powerful tool kit for rapid prototyping and virtual world testing that can yield production products faster, better, and at lower costs.”

“We use a variety of 3D printing methods for orthopedic device prototyping. We use plastic 3D printing to make initial prototypes to test form, fit, and function before machining metal,” said Bishop. “It allows for speed and to catch any major mistakes before investing the resources into making an actual fully functioning prototype. We also use metal 3D printing for prototyping on in-house equipment. This offers advantages with speed and the ability to produce some things that couldn’t be produced with conventional machining.”

“If requested, we 3D print parts to give the OEMs something to touch and feel in their hand prior to prototyping,” said Gredick. “We use 3D printing more for fixturing and internal needs. It would be nice to move in this direction more with the customers.” However, he also noted some obstacles in using the much-heralded additively manufactured rapid prototyping strategy.

“It is not representative of the final production design,” Gredick continued. “An example of this is the inability to hold close tolerances, or create the right surface finish, which may be critical to the design.”

Bishop also stressed both the monetary and structural design concerns of using 3D printing to prototype a device. “3D printing can be a costly service, although it is getting less expensive than it used to be.” He continued, “It is also tough to render fine detail and tight tolerances. The surfaces are much rougher than a machined surface—requiring polishing and/or secondary machining for those fine details, tight tolerances, and finer surface finishes. Another downfall can be material strength. There is sometimes a substantial strength difference between a 3D-printed component and a component machined from solid billet stock.”

It’s difficult to collude the hype and practicality of additive manufacturing—even with an application like prototyping, where the method has already proven considerably successful. 3D printing can potentially provide low-cost, low-volume manufacturing, quick iterations, and shorten overall lead times. But orthopedic devices vary so much in size and shape that the technology isn’t quite able to fully support the full breadth of orthopedic technologies’ dimensions.

“There are some geometries that are not suitable for 3D printing,” cautioned Duhaime. “Long tubular products can’t be fabricated, and there are some material limitations in alloy, strength, and finish.”

Getting Clinicians Involved
Ultimately, orthopedic devices will end up in the hands of the clinicians who place or implant them. Because of this, it definitely makes sense to lend a clinical eye to the early design and development phases in order to determine factors like procedural efficacy and potential for complications once the device has been installed. But it may also be practical to include clinicians in the later stages of device development, like prototyping. Though it seems not many prototyping service providers are bringing orthopedic surgeons into the lab, it’s not completely unheard of to involve them.

“Normally, the OEM works with the surgeons in the design phase, but a few Triangle team members had the opportunity to get involved in a cadaver lab with the surgeons,” recalled Gredick. “As a manufacturer, it benefits us in giving constructive feedback to the OEM when going through the DFM process. This gives us the direct feedback from the end user—which the manufacturer normally does not receive—just the engineer’s interpretation of this feedback.”

“Our products are developed in collaboration with our OEM implant customers and tailored to their specifications because the instruments must be configured to work with their specific implants (plates, screws, connectors), and are integral to the 510(k) filing,” explained Schultz. “But when we develop a new disposable procedural kit, the end user surgeons are a key part of the design input and output process. We want to get their feedback with VoC and cadlab testing to understand how to optimize clearances and navigation, geometry, tactile feel, aesthetics, and more. It’s a very iterative and fast-paced environment.”

Naturally there are a whole host of differences when consulting with a surgeon as opposed to an OEM during the prototyping phase. A surgeon will simply ask different questions about manufacturing an orthopedic device than a manufacturer would. OEMs might be more concerned with regulatory, time-to-market, and cost concerns. A clinician will likely lean just a little more heavily on the ergonomics of installing the device, its potential for failure, and—due to the more personalized orthopedic landscape—the ability to customize the device to an individual patient once an initial prototype has been developed. Ideally, both the OEM and clinician would be involved in the prototyping phase.

“The major differences between a surgeon and an industry customer are that their technical knowledge isn’t as strong as an industry customer, they may have tighter budgetary requirements, and lack of knowledge of quality and regulatory requirements,” said Bishop. “With surgeons, we often work from discussions with them and/or napkin sketches to bring their ideas to life. Having design, prototype manufacturing, and quality and regulatory teams in-house allows us to get them through the whole process and make them successful quickly. It is our philosophy to help our customers make their prototype function as intended, which sometimes means not always just making it to print. We ensure that our team consists of not only skilled people, but problem-solvers and innovators alongside our customers and engineers as well.”

Looking to the Future
It may be prudent to think of today’s orthopedic device prototyping process as a prototype itself. As industry lead times shrink and competition swells, today’s “rapid” prototyping might be considered sluggish in the next few years. Additive manufacturing has burgeoned enough in the orthopedic space to make it an extremely viable prototyping method, but it will undoubtedly become even faster with time. Models made during the prototyping phase are even beginning to approach the quality of commercial products.

“Additive manufacturing is going to continue to make rapid advancements and become a staple in the prototyping industry,” predicted Bishop. “As components also become more advanced, the need and advancements of multi-axis machining are going to come into play more as well. Multi-axis machines allow for parts to be produced with less set-ups allowing for faster production and less tolerance stacks. We try to stay ahead of the curve and make prototypes with similar methods used in production machining.”

“Parts are getting smaller and more complex with tighter tolerances and more exotic materials,” observed Duhaime. “We expect more reusable devices to lower cost on a per-patient basis.”

“Personalized medicine has arrived and there is no turning back. We are just seeing the tip of the glacier,” asserted Schultz. “It is ushering in a new wave of design and development tools that will shorten design and production times and improve outcomes. It will allow implants to be made in near real-time to fit a person’s anatomy or condition. Instruments, too, will be developed much faster for certain procedure types. Single-use (disposable) instruments and kits in sterile pack trays and pouches will become the standard in orthopedics to reduce cost, ensure pristine instruments for every implant, promote OR efficiency, and to drive implant OEM sales.”